Answer: Anywhere you feel comfortable with.
In the end its what you are willing to do for your child. I have a 7 week old baby boy. I would do anything for him to make him happy and be a succeeful adult. I do think alot of that post pardum depression is caused because to many "experts" are telling you what you should feel and do with your child. You should always be up to hearing people out about what should be done with children but don't be upset cause you cant breast feed, or simply don't want too. Or that your child sleeps with you instead of his own bed. Or you spank when others says its horrible. You should always keep your child healthy, happy and well mannered in my opinion.
My son sleeps with me and will sleep with me until I or himself feels he is ready to sleep in his own room. And I dont let others make me feel bad or guilty for doing that. Nothing wrong in showing your child you are there for them. I also rock him back to sleep in the middle of the night after a feeding, and talk to him while I rock him. My touch and voice makes him comfortable and I think its the least I can do for him, after such great joy he has filled my heart with. Its a little selfish too I enjoy his touch as well, I love him sleeping next to me as I had loved him sleeping in my belly. I miss that closeness as much as he seems too, and sleeping together helps. But co-sleeping has to be agreed with both parents, fathers need to be on board as well, fathers have just as much say in your son or daughter as you do. But don't let others make you feel bad cause your not doing it there way.